High speed printing mechanism



Dec. 13, 1966 4 Sheets-Sheet 1 ori inal Filed Sept. 16, 1965 Dec. 13, 1966 c. A. CHRISTOFF ETAL 3,291,042

HIGH SPEED PRINTING MECHANISM Original Filed Sept. 16, 1963 4 Sheets-Sheet 2 PIE- Q;

IN VEN TOR. (fie/J A (HE/5701 7 JO/M/ 0 GEAR/ 487 A) a 454M A T Tye/v5 7 Dec. 13, 1966 c. A. CHRISTOFF ETAL 3,291,042

HIGH SPEED PRINTING MECHANISM Original Filed Sept. 16, 1963 I 4 sheets-sheet a BY ZJ 2J4 A TTOE/VL Y Dec. 13, 1966 c. A. CHRISTOFF ETAL 3,291,042

HIGH SPEED PRINTING MECHANISM Original Filed Sept. 16, 1963 4 Sheets-Sheet 4 INVENTOR.

COUNTER COMPARISON GATE BUFFER STO RAGE one/s )1. 0/8/6705 Jo/m/ a ear/Mme? SUPPLY "-60 REVERSIBLE POWER ArraeA/gr United States Patent 3,291,042 HIGH SPEED PRINTING MECHANISM Chris A. Christotf, San Gabriel, and John D. Gearheart, Covina, Califi, assignors to Clary Corporation, San Gabriel, Calif., a corporation of California Original application Sept. 16, 1963, Ser. No. 308,937, now Patent No. 3,253,539, dated May 31, 1966. Divided and this application Aug. 17, 1965, Ser. No. 487,649

Claims. (Cl. 10193) This is a division of application Serial No. 308,937, filed on September 16, 1963, and since matured into Patent No. 3,253,539, issued on May 31, 1966.

This invention relates to high speed data printers of the type incorporating a rotating type drum having a plurality of peripheral columns of type elements thereon. A printing hammer is provided to effect an imprint of a selected type character in one column and is then shifted to effect an imprint of a selected type character in the next column, etc. Data to beprinted is represented by coded signals obtained from a computer, register or the like. Such data is compared with coded signals representing the different type elements as such elements pass under the printing hammer. When a match is obtained the hammer is actuated to imprint the selected character on a record medium.

A principal object of the present invention is to provide a high speed printer of the above type which is portable, highly compact and adapted to be manufactured in a relatively light and small package.

Another object is to provide a printer of the above type which is reliable, rugged, and yet inexpensive to manufacture and service.

The manner in which the above and otherobjects of the invention are accomplished will be readily understood on reference to the following specification when read in conjunction with the accompanying drawings, wherein:

FIG. 1 is a front view, with parts broken away, of a printer embodying a preferred form of the present invention.

FIG. 2 is a transverse sectional view taken along the line 2-2 of FIG. 1.

FIG. 3 is a transverse sectional view taken along the line 33 of FIG. 1, illustrating part of the paper advancing mechanism.

FIG. 4 is a sectional plan view taken along line 44 of FIG. 1, illustrating the type hammer escapement mecha- FIG. 5 is an enlarged sectional plan view taken substantially along the line 55 of FIG. 3, illustrating part of the hammer actuating mechanism.

FIG. 6 is a sectional view taken substantially along the line 66 of FIG. 3.

FIG. 7 is a transverse sectional view illustrating part of the type hammer shifting mechanism and is taken substantially along the line 77 of FIG. 1.

FIG. 8 is an enlarged transverse sectional view taken substantially along the line 88 of FIG. 1, illustrating the printing ribbon advancing mechanism.

FIG. 9 is a schematic view illustrating the basic circuit connections for the printer.

Referring to the drawings, the printer comprises a frame including end walls 11 and 12 and a back side wall 13.

A supply roll 14 of paper 9 is carried on a suitable spool located in the lower portion of the frame and rotatably mounted between the end Wall 11 and an auxilary frame wall 19. The paper is guided over a guide roll 15 and around a rotatable type drum 16 where data is selectively printed thereon. After passing over the drum, the paper is guided out through a slot 17 in a top wall 18.

The type drum 16 has a plurality of slightly raised type 3,291,042 Patented Dec. 13, 1966 characters 20 (FIG. 1) arranged in longitudinally extending rows and in circumferentially extending columns. Preferably, the type characters are identical in each row and progress in value around each column. The drum is hollow and is rotatably mounted at its lefthand end on a bearing 21 supported by a bracket or arbor 22 extending from the rear side wall 13. The righthand end of the drum is rotatably mounted on a bearing 23 supported by a stationary arbor 24. The latter is attached to the wall 12 and carries at its lefthand end the stator portion of an electric motor 25 located within the type drum. The rotor of the motor carries a rotatable drive shaft 26 at the lefthand end of the motor to which is attached a metal hub member 27 fitted within the type drum and held in driving relation with the drum by a spring pressed drive key 28 which normally fits in a keyway 30 in the drum. The hub 27 thus supports the lefthand end of the motor within the drum.

The bracket 22 has an inwardly projecting extension 31 on which are mounted a pair of electric induction pickup heads 32 and 33 of conventional construction. The hub member 27 is provided with a series of equally spaced segments 34 which are angularly spaced to generate a pulse in the head 32 each time a new row of type char acters pass a printing point P. As shown, the type drum is constructed to print numerals from 0 to 9. However, the drum could equally well be constructed to print alphanumerical characters and others, in which case the hub member would be divided into a correspondingly larger number of segments.

A metal reset pulse generating arm 35 is attached to the motor shaft 26 and generates a pulse in the pick-up head 33 each time the drum makes a complete revolution.

It will be noted that the drum, being formed of metal, performs the additional function of shielding the motor and pick-up heads from emitting electromagnetic radiations which might cause radio transmission interference.

The paper is provided with perforations 36 along the opposite edges thereof which are engaged by pins 37 car ried by sprocket rings 38 and 39 rotatably mounted on the type drum at opposite ends thereof. The sprocket rings are of slightly larger outer diameter than the type drum 16 so that the paper 9 is normally held out of contact with the type characters on the drum.

The sprocket rings are normally held stationary and are incrementally advanced to line space the paper by an advancing mechanism generally indicated at 40, FIGS. 3 and 6, which is basically similar to that disclosed and claimed in the copending application of R. E. Busch, Serial No. 286,878, filed on May 22, 1963, to which reference may be had for a complete disclosure of such mechanism.

Generally, the mechanism 40 comprises a gear 141 rotatably mounted on a stationary rod 142 and meshing with the gear of the sprocket ring 39. The gear 141 has integrally formed thereon a sleeve 143 which is also rotatably about the rod 142 and has mounted at its opposite end a second gear (not shown) similar to gear 41 for driving the sprocket ring 38 in timed relationship with ring 39. A suitable spring detent device (not shown) is provided to detent the gear 141 in different positions corcorresponding to the line spacing of the paper.

The gear 141 has a series of equally spaced radially extending V-shaped teeth 144 which mate with identical teeth 145 formed on a pawl element 46, also rotatably mounted on the rod 142. The pawl element has a second set of radially extending V-shaped teeth 47 which are of coarser pitch than the teeth 145 and which mate with identically shaped teeth on a wedging element 48 also rotatably mounted on the rod 142. A sleeve limits rightward movement of the wedging element.

The sides of the teeth 47 preferably extend at substantially the same angle to the axis of the rod 142 as the teeth 144 and 145.

The pawl 46 is continuously oscillated about the rod 142 an amount equal to the pitch of the teeth 145 and 146 and for this purpose it is provided with an arm 51 pivotally connected by a link 52, FIG. 3, to a cam follower 54. The latter is fixed on a rock shaft 55 and carries rollers 56 which cooperate with a pentagon-shaped cam 57 driven continuously by the type drum through a gear 146 attached to a shaft 147 carrying the cam. The gear 146 meshes with a gear 148 integral with the drum 16.

The wedging element 48 is normally held in a noneffective position, shown in FIGS. 3 and 6, under the influence of a stationary permanent magnet 58 through a pair of soft iron extensions 60 which are normally engaged by a soft iron armature 61 integral with the wedging element, against the action of a tension spring 62. In this condition, oscillation of the pawl element 46 will result in an idling movement in which the pawl will merely float axially a slight amount during its rocking movement without transferring movement to the gear 141.

Upon momentarily energizing a pair of coils 63 on the magnet extensions 60, as will be described later, the magnetic flux exerted by the magnet 58 will be overcome permitting the spring 62 to rock the wedging element 48 counterclockwise (FIG. 3) to cam the pawl element 46 leftwardly so as to mesh the teeth 44 and 45 together. Thus, upon the following oscillation of the pawl, the gear 141 will be driven to advance the sprocket rings 38 and 39 and paper one line space. During the return movement of the parts, the wedging element will be returned to its position of FIG. 3 wherein the armature 61 will again engage the extensions 60 to again retain the wedging element in non-effective condition.

Means are provided for serially transferring imprints of selected type characters from the type drum 16 to the paper and for this purpose a hammer device generally indicated at 66, FIGS. 1 and 2, is provided.

The hammer is of relatively light mass and comprises a pair of thin spaced arms 67 slideable along a tubular shaft 68 which is supported for rocking movement in bearings formed in the end frame plates 11 and 12. Each arm has a key formation 168 which is movable along a mating longitudinally extending slot in the tube. The arms 67 are held in spaced relation to their upper ends by a platen piece 70 which is effective to transfer an imprint to the paper during counterclockwise rocking of the hammer.

An endless ribbon 71 is wrapped over an idler roller 72, rotatably supported between the upper ends of the arms 67 and an inking impregnated roller 73 of felt or the like. The latter is carried by a sleeve 74 rotatably mounted on the shaft 68 and provided with a ratchet wheel 75 which is incrementally advanced to advance the printing ribbon past the platen piece 70. For this purpose, the ratchet wheel is engaged by a blade 76 extending along the length of the drum 16. The blade is mounted at its ends on leaf spring 77 carried by levers 78 which are pivotally supported at 80 on the end walls 11 and 19. The latter levers are pivotally connected to hell cranks 82 pivotally supported on the shaft 68 and are connected by links 83 to arms 84 suitably fastened to the oscillating shaft 55 whereby to cause oscillation of the blade 76 about the pivot supports 80 to incrementally advance the roller 73 and printing ribbon 71.

Means are provided under control of differently timed pulses to oscillate the tubular shaft 68, causing the hammer device 66 to effect imprints of selected type characters on the drum 16 as they pass the printing point P. For this purpose, a selectively operable oscillating drive unit generally indicated at 85, FIGS. 3 and 5, is provided. The latter is basically similar to the mechanism described and claimed in the copending application of R. E. Busch,

S.N. 286,612, filed June 10, 1963, and it will therefore be only briefly described herein.

The drive unit 85 comprises a Wedge disc 86, a driving disc 87 and a driven disc 88, all mounted in side relation on the oscillating shaft 55. Retainer discs 90 and 91 are secured on the shaft on opposite ends of the discs 86 and 88 to limit axial movement of the latter.

The adjacent faces of the discs 86 and 87 are provided with intermeshing, radially extending V-shaped teeth 92. Likewise, the adjacent faces of the discs 87 and 88 are formed with intermeshing V-shaped teeth 93 similar to the teeth 92.

The driving disc 87 is suitably keyed in a manner not shown to the shaft 55 whereby it is constrained to Oscillate with the shaft but is free to move axially a slight amount. The driven disc 88 has an arm 94 thereon which is connected by a link 95 to an arm 96 fastened to the tube 68. The wedging disc 86 has a soft iron armature 97 integral therewith which cooperates with a stationary permanent magnet 98 through soft iron extensions 100 to normally hold the wedging disc in a counterclockwise rocked position, as'shown in FIG. 3, against the action of a tension spring 101. In such position of the disc 86, it will be ineffective to wedge the driving disc into driving engagement with the driven disc and therefore the driving disc will merely oscillate in an idle manner in sliding engagement with the teeth of the discs 86 and 88, during which time it will float axially under the camming effect of the teeth on the discs 86 and 88. However, upon energization of a pair of coils 102 wound on the extensions 100, the magnetic flux developed by the magnet 98 is counteracted, permitting spring 101 to urge the wedging disc clockwise to wedge the driving disc into driving engagement with the driven disc whereby to oscillate the tubular shaft 68 and thereby cause the hammer 66 to impinge against the paper so as to print an image of the type character passing immediately thereunder.

The print pulse applied to the coils 102 is only momentary and therefore as the shaft 55 returns the various discs 86, 87 and 88 to their counterclockwise rocked positions the armature 97 will again engage the extensions 100 where they will be magnetically latched against the action of spring 101.

As an incident to each printing operation of the hammer, it is later spaced to the right to align with the next column of type characters on the drum. For this purpose, one of the hammer arms 67 has a depending bifurcated pawl extension 103, the legs of which cooperate with a pair of stationary toothed escapement racks 104 and 105 (FIG. 4) suitably mounted, in a manner not shown, on the machine frame.

Means are provided for moving the hammer unit to the right when released from the escapement teeth and comprises a reversible direct current drive motor 106 which drives a belt pulley 107 through a friction slip clutch 108. An endless belt 110 is wrapped over the pulley 107 and one strand thereof is guided over a guide pulley 111 and through the tube 68 where it is attached at 112 (FIG. 2) to the key formed on one of the hammer arms 67. This strand of the belt passes around the tension pulley 113 carried on an arm 114 pivotally supported at 115 and urged counterclockwise by tension spring 116. The second strand of the belt extends through the bifurcated portion of the hammer extension 103 and is guided over a second guide pulley 117 onto the drive pulley.

When the hammer unit is actuated to effect a printing impression, the pawl extension 103 recedes from engagement with an adjacent tooth on the escapement rack 104 and moves into blocking relation with an adjacent escapement tooth on the rack 105. It will be noted that the teeth of the two racks 104 and 105 are out of line with each other so that the hammer will be advanced approximately one-half the distance between two adjacent columns of type characters and will be aligned adjacent one of such columns just prior to the printing impression. Thereafter, as the hammer is returned to its normal position as shown in FIG. 2, the pawl extension 103 recedes from the'rack 105 and again limits against the next adjacent tooth on the rack 104 under the pull of belt 110.

When the hammer reaches its righthand limit position, it closes a normally open switch 118. FIG. 9, thus completing a circuit to the aforementioned coils 63 to effect a paper advance and at the same time sets a bistable switch unit 120 to cause reversal of a direct current power supply 130 for the motor 106. Accordingly, the motor will drive the belt 110 a reverse direction to shift the hammer unit to its lefthand position where it will close a second normally open switch 131. The latter will reset the bistable unit 120 to cause a reversal of motor 106 to again urge the hammer to the right into its first printing position.

As stated hereinbefore, the inductive pick-up head 32 generates a pulse each time a row of type characters on the drum pass the printing point P. Such pulses are fed to a counter 132 whose output indicates the value of each of the type characters passing the printing point at the moment. The ouput of the counter 132 is applied to a comparison gate 133 of conventional construction where it is compared with the output of a register 134 containing the data to be printed. When the output of the counter matches the value registered by the register 134, a pulse is applied over line 135 to energize the coils 102 and thus effect a printing operation.

Reset head 33 generates a pulse at the start of each revolution of the drum and is effective to reset the counter 132 to therefore assure that the counter is in time with the drum.

Although the invention has been described in detail and certain specific terms and languages have been used, it is to be understood that the present disclosure is illustrative rather than restrictive and that changes and modifications may be made without departing from the spirit or scope of the invention as set forth in the claims appended hereto.

Having thus described the invention, what is desired to be secured by United States Letters Patent is:

1. Printing mechanism comprising the combination of a type drum having a plurality of different type characters therearound, means for advancing said drum about its axis, a printing hammer having a platen portion, means for guiding said hammer along the length of said drum, means for guiding a record medium between said drum and said hammer, an endless printing ribbon, means on said hammer guiding said ribbon thereover and past said platen portion in a direction at right angles to the length of said drum, said means constraining said ribbon to move bodily with said hammer along the length of said drum, means for actuating said hammer whereby to cause said ribbon and said platen portion to force said record medium into printing engagement with a said type character, and means for advancing said printing ribbon over said hammer.

2. Printing apparatus comprising the combination of a type drum having a plurality of peripherally extending columns of type characters thereon, means for advancing said drum about its axis, a printing hammer having a platen portion, means for guiding said hammer along the length of said drum, means for guiding a record medium between said drum and said hammer, an endless printing ribbon, means on said hammer guiding said ribbon thereover past said platen portion in a direction at right angles to the length of said drum and constraining said ribbon to move bodily with said hammer along said drum, means for actuating said hammer whereby to cause said ribbon and said platen portion to force said record medium into printing engagement with a said type character in one of said columns, means for advancing said ribbon over said hammer, and means responsive to said actuation of said hammer for advancing said hammer from cooperative relation with one of said columns into cooperative relation with another of said columns.

3. Printing mechanism comprising the combination of a type drum having a plurality of peripherally extending columns of type characters thereon, means for advancing said drum about its axis, a printing hammer having a platen portion, means for guiding said hammer along the length of said drum, means for guiding a record medium between said drum and said hammer, an endless printing ribbon, means on said hammer guiding said ribbon thereover past said platen portion in a direction at right angles to the length of said drum and constraining said ribbon to move bodily with said hammer along said drum, means for actuating said hammer whereby to cause said ribbon and said platen portion to force said record medium into printing engagement with any selected one of said type characters, means for advancing said endless ribbon over said hammer, a stationary toothed escapement rack, and an escapement pawl on said hammer cooperable with said rack, said pawl being effective to escape said hammer from one tooth of said rack to another as an incident to said actuation of said hammer.

4. Printing mechanism comprising the combination of a type drum having a plurality of different type characters therearound, means for advancing said drum about its axis, a shaft extending parallel to the length of said drum, a printing hammer slideably keyed to said shaft for movement therealong, said hammer having a platen portion, means for guiding a record medium between said type drum and said hammer, a roller rotatably mounted on said shaft and constrained to move with said hammer along said shaft, an endless printing ribbon guided over said roller and said hammer for bodily movement with said hammer, said ribbon extending over said platen portion, means for rocking said shaft whereby to cause said ribbon and said platen portion to force said record medium into printing engagement with a selected one of said type characters, and means for advancing said endless ribbon over said roller and said hammer.

5. Printing mechanism according to claim 4 wherein said roller comprises an ink absorbent material effective to transfer ink to said printing ribbon.

6. Printing mechanism according to claim 4 comprising a stationary escapement rack, and an escapement pawl on said hammer cooperable with said rack, said pawl being effective to escape from one of the teeth of said rack to another upon said rocking of said shaft.

7. Printing mechanism comprising the combination of a type drum having a plurality of different type characters therearound, means for advancing said drum about its axis, a shaft extending parallel to the length of said drum, a printing hammer slideably keyed to said shaft for movement therealong, said hammer having a platen portion, rollers adjacent opposite ends of said hammer and constrained to move with said hammer, an endless printing ribbon guided over said rollers and over said platen portion for bodily movement with said hammer, means for rocking said shaft whereby to cause said ribbon and said platen portion of said hammer to force said record medium into printing contact with a selected one of said type characters, means for advancing one of said rollers whereby to advance said printing ribbon past said platen portion, and means for advancing said hammer along said shaft.

8. Printing mechanism according to claim 7 wherein one of said rollers comprises ink absorbent material effective to transfer ink to said printing ribbon.

9. Printing mechanism comprising the combination of a type drum having a plurality of different type characters therearound, means for advancing said drum about its axis, a shaft extending parallel to the length of said drum, a printing hammer device slideably keyed to said shaft for movement therealong, said device comprising a pair of spaced arms, a platen element between said arms and a pair of rollers rotatably supported intermediate said arms; said rollers being located on opposite sides of said platen element, an endless printing ribbon guided over said rollers and over said platen for bodily movement with said hammer, means for rocking said shaft whereby to cause said ribbon and said platen element to force said record medium into printing contact with a said type character, and means for advancing one of said rollers whereby to advance said printing ribbon past said platen element.

10. Printing mechanism comprising the combination of a type drum having a plurality of different type characters therearound, means for advancing said drum about its axis, a shaft extending parallel to the length of said drum, a printing hammer device slideably keyed to said shaft for movement therealong, said hammer device comprising a pair of spaced arms, a platen element between said arms, a first roller rotatably mounted between said arms on one side of said platen element, a second roller rotatably mounted on said shaft intermediate said arms on the opposite side of said platen element, and an endless printing ribbon supported by said rollers and guided over said platen by said rollers for movement in a direc tion at right angles to the length of said drum; one of said rollers comprising an ink absorbent material effective to transfer ink to said printing ribbon, means for rocking said shaft whereby to cause said ribbon and said platen element to force said record medium into printing contact with a said type character, means for rotating one of said rollers whereby to advance said printing ribbon past said platen element, and means for advancing said hammer along said shaft.

References Cited by the Examiner UNITED STATES PATENTS 1,958,764 5/1934 Mosfelt et a1 197-l53 2,656,240 10/1953 Hall 10l93 X 3,135,195 6/1964 Potter 10193 ROBERT E. PULFREY, Primary Examiner.

20 W. F. MCCARTHY, Assistant Examiner. 

1. PRINTING MECHANISM COMPRISING THE COMBINATION OF A TYPE DRUM HAVING A PLURALITY OF DIFFERENT TYPE CHARACTERS THEREAROUND, MEANS FOR ADVANCING SAID DRUM ABOUT ITS AXIS, A PRINTING HAMMER HAVING A PLATEN PORTION, MEANS FOR GUIDING SAID HAMMER ALONG THE LENGTH OF SAID DRUM, MEANS FOR GUIDING A RECORD MEDIUM BETWEEN SAID DRUM AND SAID HAMMER, AND ENDLESS PRINTING RIBBON, MEANS ON SAID HAMMER GUIDING SAID RIBBON THEREOVER AND PAST SAID PLATEN PORTION IN A DIRECTION AT RIGHT ANGLES TO THE LENGTH OF SAID DRUM, SAID MEANS CONSTRAINING SAID RIBBON TO 